Subjects recruited will be non-asthmatic controls or mild allergic asthmatics using beta-agonists, mostly on an "as needed" basis. Selection criteria will include good general health by medical history and physical examination, no history of smoking, and the absence of respiratory infection in the preceding 6 week period. Subjects will undergo serologic testing and must have a negative test for neutralizing antibodies to RV16 to participate in all but one study of the project.